Citrus fruits are generally harvested by hand picking and the conventional harvesting method includes the use of pick sacks, pallet tubs, and expensive in-grove vehicles with booms. More specifically, during a typical harvesting operation, a citrus fruit picker picks the fruit from a tree and places it in a pick sack which is swung over his/her shoulder and which has, for example, a sixty pound capacity. When the pick sack is full, the fruit picker carries it to a pallet tub empties the fruit into the pallet tub, and then returns to the next tree with an empty sack to repeat the cycle.
A full pallet tub will commonly have a ten box capacity and will weigh about nine hundred pounds. A full tub will usually be emptied shortly after it is filled by an expensive in-grove vehicle with a boom, such as a field truck or "loader" (sometimes also called a goat) which moves along with the pickers during the harvesting process. A loader is a modified truck equipped with a rotatably mounted hydraulic boom specifically designed to lift and empty a fruit filled pallet tub into the loader's bed. The loader's bed is designed so that it may empty the fruit into a trailer which then hauls the fruit to a processing plant.
In a typical harvesting system, a large number of pallet tubs are strategically placed throughout the grove so that they will be substantially filled during a harvesting operation. Thus, the distance between the respective pallet tubs will be determined by the amount of citrus fruit on the trees between the pallet tubs. For example, in established citrus groves with "high density trees", the tubs will be arranged relatively close to one another. More particularly, a "high density" orange grove, or one having trees which are eight to ten years old, will yield about 1,100 oranges per tree. A ten box pallet tub will hold about 2,200 oranges which represents the average production from two "high density" orange trees. Thus, the pallet tubs may be arranged between every other tree in such an orange grove and this arrangement results in a very short walking distance between the tree from which the fruit is being picked and the pallet tub into which the fruit is emptied. Because the time when a worker walks is essentially dead time in the harvesting season, the shorter the walking distance, the more productive a picker.
Conversely, in young citrus groves with "low density" fruit trees, the pallet tubs will be spaced further apart. More particularly, a low density orange grove will contain young trees which are two to four years old and which average about eight to twelve oranges a tree per year. Thus, a picker would have to harvest about two hundred and twenty trees to fill one "ten box" or "2,200 orange" pallet tub and a picker will have to walk about 3,520 feet to fill one pallet tub. (Assuming that the trees are spaced about sixteen feet apart). Needless to say, this significant walking distance reflects negatively upon a picker's efficiency. It is important to note that this inefficient picking pattern can not be cured by simply providing more pallet tubs because of the significant cost of operating a loader. More particularly, if a loader was to move along with a small group of "low density" pickers, this expensive piece of equipment would either be idle or would inefficiently be continuously moving partially filled pallet tubs as the pickers move from tree to tree.
For these reasons, citrus growers are commonly charged two to three times the normal picking rate to have their low density, young trees picked. As a result, most growers cannot afford to justify the additional cost to have the fruit picked from their young trees until the trees reach a minimum production of about 30 oranges per tree.
In the past, high density groves were gradually replaced with low density groves thereby comfortably allowing this practice. However, a series of freezes during the past eight years have substantially reduced the number of high density groves and precipitated a sharp increase in the number of newly planted citrus groves. As such, the citrus industry has recently been forced to look to low density groves to satisfy the demand for citrus products, such as orange juice concentrate. However, at the same time, changes in the Immigration Act have made it extremely difficult and expensive to harvest citrus fruit from these low density citrus trees.
In response to these unfortunate freezes, the citrus industry has recently begun to reconsider the advantages of planting trees more closely together in rows and arranging these rows of trees so that the aisles therebetween are narrower. For example, groves have been planted with trees spaced eight feet apart with fifteen foot wide aisles. This increased compactness is believed to provide some protection against frost conditions and reduces the walking distances required for picking these young trees. However, this arrangement also creates harvesting complications because it is difficult to move and position the pallet tubs and difficult to maneuver and use the loader.
The present invention provides a fruit harvesting apparatus which is particularly adapted for harvesting young "low density" citrus trees. The apparatus includes a vehicle having a front end and a back end, and means for moving the vehicle along the ground. A tray is mounted to the front end of the vehicle for receiving the picked fruit and a pivotable hopper is mounted to the back end of the vehicle for temporarily storing the picked fruit. A transfer system is provided for transferring picked fruit from the tray to the hopper. The bottom wall of the tray does not include a horizontal opening.
A fruit harvesting apparatus according to the present invention allows four to ten workers to walk alongside the machine. For example, two to five workers could walk on either side, simultaneously picking and continuously placing the picked fruit in the tray as the machine is driven down the row of trees being picked. The production from a picker is increased because the invention reduces the distances walked and thus affords the picker more time and energy to pick fruit. The person driving the vehicle can also supervise the pickers and in part control the speed of the picking process by controlling the speed of the vehicle.
Initial experimental field tests indicate the present invention enable six pickers and one person driving the machine to harvest about 115,000 oranges a day from young trees. This output is a substantial increase from that realized with the current method of using pallet tubs and a loader which requires about 15 to 18 pickers and one driver to pick the same volume of oranges from young trees in a day. This increased output is reflected in cost savings to a citrus grower and these cost savings are further magnified by the fact that the invention eliminates the use of pallet tubs and expensive loaders.
The present invention additionally provides the flexibility of custom designing the width/shape of the tray to work within the various planting configurations employed in different groves. More particularly, the tray is removably mounted on the vehicle to allow a tray of different size/shape to be selectively mounted thereon. In this manner, a tray may be chosen which has a geometry compatible with the configuration of the grove being picked. For example, in a grove having narrow aisles, a tray of reduced width would be selected and mounted on the vehicle.
Applicants have further discovered that in such a fruit harvesting apparatus, the design of the tray is an important operational concern. For example, the clogging of fruit as it enters the transfer system is extremely undesirable and the chances of such clogging commonly escalate as the size of the crew (and thus picked fruit volume) increase. A typical cause of such clogging will occur when the connection between the tray and the transfer system requires an elbow, especially in pneumatic systems. Additionally, clogging is believed to occur when the area of the bottom wall of the tray does not evenly distribute and control the flow of fruit as it travels towards the connection between the tray and the transfer system. More particularly, fruit sometimes gathers along side of the tray opening and wedges on the edge of the tray opening when two or more pieces of fruit try to enter the transfer system at the same time.
The present invention is believed to solve these clogging problems by providing a smooth transition surface between the tray and the transfer system whereby the use of an elbow is not required. Additionally, the bottom wall of the tray is provided with channel-forming sections which form a channel. The channel restricts the amount of fruit that can flow towards the opening and aligns the fruit with the tray opening prior to the time the fruit enters the pneumatic transfer system. As a result, the suction from the transfer system will travel into the channel whereby it acts as a continuation of the transfer system and gradually pulls the picked fruit from the channel through the opening and into the transfer system. The lower wall of the channel is substantially planar and slopes downwardly towards an end edge of the channel which at least partially defines the tray opening. The inclusion of such a channel in the tray is believed to improve the efficiency of the tray by controlling the volume of fruit flowing towards the tray opening and thereby helping to eliminate the clogging of the fruit as it enters the transfer system. The channel may be directed towards either a back wall or a side wall of the tray depending on the application. Additionally, in either case, the opening may be positioned in front of, in back of, or aligned with the back/side wall.
Furthermore, the bottom wall of the tray is provided with discrete section(s) which slope downwardly towards this channel. These sections will help to align the fruit as it travels into the channel. The slope of the bottom wall may be selectively adjusted by including a slope-adjusting device which pivotally adjusts the slope of the bottom wall relative to the side walls, as well as the lower wall of the channel. This slope-adjusting device may include a mechanical, manual or automatic slope-determining assembly.
Another significant concern in the design of the tray is its height from the ground. More particularly, it is important that the height of the tray be such that lifting and emptying a potentially heavy container, such as a pick bag, does not unduly task the fruit picker. The present invention provides a tray which may be mounted about 2.5 feet from the ground, the same average height of the conventional pallet tub which is about 2.5 feet. In this manner, the workers may easily empty their pick sacks into the tray. To achieve these height requirements, the bottom wall may include symmetrical sloping sections whereby only half the height of the walls is necessary to acquire the desired pitch, or slope, of the bottom wall.
Yet another significant concern in the design of the tray is the ability of it to accommodate a variety of vehicles such as those in which the transfer system is not centrally located. This accommodation is necessary or at least desirable due to the large capital costs associated with such vehicles, and the purpose of many growers to use existing machinery, such as boom machines or other farm equipment. The tray of the present invention is compatible with such equipment while at the same time allowing the tray to be connected to the transfer system without an elbow. More particularly, the present invention offers the manufacture and grower the option of having the tray opening directed towards either the back wall or the side wall, and in either case, located flush with, in front of, or behind, the respective wall depending on the specific structural requirements of the equipment. For example, where the back wall is used as the primary means for attaching the tray to a vehicle, the tray opening may have to be located in front or in back of the wall.
These and other features of the invention are fully described and particularly pointed out in the claims. The following descriptive annexed drawings set forth in detail certain illustrative embodiments. However these embodiments are indicative of but a few of the various ways in which the principles of the invention may be employed.